It is possible to produce a tv commercial only with Flash and Premiere? and Would I be able to make changes to the flash, like a phone number, everytime i need and then imported to premiere to produce the final video?
No. There is ni Dynamic linking between flash and Pr.
Unless; the flash is a bacjground and your variables are higher layers in Pr.
You might consider doing the animation in AE and Dl that into Pr. A bit more flexabiity than flash